It has now been established that, because of their high coefficient of action on ozone, CFCs will have to be replaced in the long term by refrigerant fluids which do not contain chlorine and which consequently have no effect on stratospheric ozone.
1,1,1,2-Tetrafluoroethane (HFA 134a) has already been proposed as a substitute for dichlorodifluoromethane (CFC 12). However, bearing in mind its thermodynamic performance which is lower than that of CFC 12 (in particular its coefficient of performance) HFA 134a does not represent a fully satisfactory solution if the running costs of a refrigerating plant are to be reduced to a minimum; this is particularly the case with household compression refrigerators which at present employ CFC 12 as refrigerant fluid and for which the designers are subjected to increasingly great energy consumption constraints.